The invention relates to a special design of a hermetic refrigeration compressor provided, in particular, for use in connection with household refrigerating and/or deep-freezing appliances, namely that compressor part which comprises the refrigerant suction components within the cylinder of the compressor.
It is well known that the refrigeration compressors used in refrigerating and deep-freezing appliances are standardized products, wherein compressor manufacturers have incessantly and persistently endeavored to allow such products to become more and more competitive in terms both of general efficiency and costs by constant improvements to the last detail.
One of the most critical components used in such refrigeration compressors undoubtedly is the refrigerant suction check valve, i.e., that valve which lets the refrigerant into the compression cylinder and, at the same time, prevents the same from flowing back from said cylinder. Such a valve usually has the form of a tongue valve made of high-strength and highly elastic steel, which is also called spring valve in the technical jargon such that the following description generally refers to a spring valve or rather a valve spring.
It is generally known that a spring valve usually is comprised of a small and extremely thin special steel plate, which in its central region has a bent indent which defines the zone constituting the valve spring proper, i.e. the movable part of the valve, and clears and seals the suction bore provided in the valve plate.
Such a thin plate is retained in its position by the provision of respective throughbores in its corners, in which suitable screw bolts can be screwed which are used for clamping the inner body of the compressor, the valve head, the valve plate, the valve spring and possibly interposed seals in a manner that the structural components mentioned will be held together practically as a single body.
This is definitely a technique known to everybody skilled in the art and does not need any further explanations.
The problem to be solved rather is related to the actual application of the valve spring, for the manufacture of which very expensive special alloys are presently used, which, however, are not specifically required for the manufacture of the whole plate. It is only the movable plate part which is comprised of a small tongue or spring as well as its transition zone acting as a hinge, which make such function-related demands that can be effectively met only by employing high-performance special alloys, which are usually very expensive.
It would, therefore, doubtlessly be of great advantage to limit the application of such alloys merely to the movable spring and the associated transition zone and, at the same time, use more cost-effective materials for the remaining part of the plate, since that remaining part is clearly less demanding in terms of performance. According to another known solution, which is effective as such, the plate of the spring valve is practically eliminated completely, keeping but its movable tongue, i.e., the spring proper, wherein said spring is then connectable with the valve plate by one or several pins which are inserted in respective bores provided in the valve plate and, at the same time, fix the movable spring.
As has become known from DE 19 613 911 C1, the spring also may comprise two bent-up lugs arranged laterally so as to be offset in the longitudinal direction of the spring, which reach into respective recesses. Likewise, it is feasible to design the valve spring symmetrically without bent-up lugs, as in correspondence with the design according to U.S. Pat. No. 5,456,287.
Such solutions, however, have the disadvantage of involving some additional manufacturing sequences such as, e.g., the realization of bores and the insertion of the respective studs. Moreover, the quite considerable costs of such studs are to be taken into account.